Billy Strings and Marcus King, two of jam, blues and bluegrass music’s most potent players, teamed up at last May’s DelFest to pay tribute to the Allman Brothers Band with a vicious take on “Midnight Rider.”

Strings does his best Gregg Allman growl as lead vocalist and also adds an intricate solo on his acoustic, before King — the leader of his namesake Marcus King Band — steps in with a fluid electric solo of his own. The Allmans collaboration is far from the first time the two musicians have joined together. At King’s Family Reunion festival near Asheville, North Carolina, last year, Strings and King delivered a knockout rendition of “Orange Blossom Special.” (King recently announced the lineup for his 2019 Family Reunion.)

DelFest, the annual celebration of string music held each spring in Maryland, marked its 12th year in 2019 and also honored the 80th birthday of bluegrass icon Del McCoury, for whom the fest is named.

Strings, who released his album Turmoil & Tinfoil in 2017, performed as part of the Ryman Auditorium’s summertime bluegrass series last week. He’s on tour through the fall and will appear at the Peach Music Fest in Scranton, Pennsylvania, and at the Newport Folk Festival in Newport, Rhode Island, in July. King, meanwhile, will join Chris Stapleton for select dates of the country singer’s All-American Road Show Tour.